Date: Wed, 24 Jun 1998 05:42:02 -0600
From: long@apo.nmsu.edu (Dan Long)
Subject: 2.5m night report 980623
                          TUESDAY JUNE 23, 1998
                     APACHE POINT OBSERVATORY SDSS 2.5m
                              OBSERVING  LOG
     The enclosure was opened at about 20:20.  The Hartmann screen was
  installed over the primary.  This combined with getting the telescope
  into position took about 1 hour.  Imager was taking data shortly before
  22:00.
     Skies were clear all night. Winds were relatively light and
  temperatures were in the mid 60s all night.  Images on the 3.5m were
  reported to be in the .75" to .9" range all night.  Most FWHM on the
  2.5m data were in the 1.3" range, with one report of 1.1".
     Hartmann data was taken until about 23:30, at which time the screen was
  removed.  The telescope was parked at the meridian until about 04:00.
  Testing was done on the software as data was taken during this time.
  At about 04:00 the telescope was moved two hours east still on the
  equator and some driftscan data was taken.  This was to verify that
  the telescope could be acurately moved to a position in all three axes
  for proper driftscan orientation.  It worked very well.  Good images
  were obtained right away with no additional tweaking.
     The move was made a bit more tedious by the fact that the windscreen
  will only track in azimuth up to speeds of about 10000 counts per second
  ( roughly 4 arcminutes per second ).  Also at slow speeds ( on the order
  of 10 counts per second ), the rotator moves in the same direction
  regardless of the sign of the move.  This makes it more difficult than it
  should to position the rotator to within a few arcseconds ( a necessary
  requirement for accurate driftscanning ).
     The telescope was closed up at 05:00.  Parked at the usual 20 degrees
  elevation for the imaging camera.  Altitude brake is on.
                                   Dan